Influence of Pre-harvest Sprays of Calcium and Potassium on the Storage Behaviour of Banana Fruits

Abstract

Aims: The aim of the study is to investigate the influence of pre-harvest sprays of calcium and potassium chlorides on the quality of banana (Musa acuminata) fruits in storage. Study Design:  The experiment was laid out in Factorial Completely Randomized Design (FCRD) with two treatments in first factor and five treatments in second factor. Each treatment is replicated thrice. Place and Duration of Study: Department of Postharvest Technology of Horticultural crops, Faculty of Horticulture, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal. The field work was conducted in the farm of AICRP on tropical fruits at Mondouri in the Nadia district, West Bengal. The experiment was conducted during December 2013 to February 2015. Methodology: Calcium chloride (1% and 2%) and potassium chloride (0.5% and 1%) was applied twice (first at time of male bud removal, second 30 days after the first spray) to the entire bunch of fruits of selected plants of two banana cultivars ‘Grand Naine’ (AAA) and ‘Martaman’ (AAB) and fruits were harvested at commercial maturity stage. Uniform size fruits from 2nd, 3rd and 4th hands of each treatment were used for the experiment in two factor Factorial Completely Randomized Design. Observations were recorded on physiological loss in weight (PLW), marketability and various biochemical characters at different stages of ripening indicated by change in peel colour as green stage (S1), yellow with trace of green (S2) and all yellow with brown spots (S3). Results: The results indicated that although treatment Martaman x CaCl2 1% (V2T3) possessed least PLW both at S2 and S3 stage, V1T3 (Grand Naine x CaCl2 1%) and V1T4 (Grand Naine x CaCl2 2%) with medium PLW had high marketability of 58.67 and 56.67%. respectively at S3 stage of ripening due to retention of significantly high level of chlorophyll at the initial stage i.e., S1 and S2. This high level of chlorophyll content enhanced the green life of V1T3 and V1T4 to 9 days and consequently prolonged the storage life to 13 days and 12 days respectively. The response of Martaman to the different treatments caused very slow level of biochemical changes compared to the observed response of Grand Naine treatments even at S2 stage. However, the chemical constituents of the fruits from different treatment combinations involving Grand Naine (V1T3 and V1T4) and Martaman at the late stage S3 are significantly different (p >0.05). Conclusion: Grand Naine variety sprayed with CaCl2 1% produced the best banana fruits with extended shelf life and proved to be the best treatment that could be recommended to growers for improved marketability storage.